Agri Kultuur August / Agustus 2016 | Page 6

https://midlandsconservanciesforum.files.wordpress.com/2013/07/notillmaize.jpg C onservation Agriculture (CA) is a set of soil management practices that minimize the disruption of the soil's structure, composition and natural biodiversity. Despite high variability in the types of crops grown and specific management regimes, all forms of conservation agriculture share three core principles. These include:  maintenance of permanent or semi-permanent soil cover (using either a previous crop residue or specifically growing a cover crop for this purpose);  minimum soil disturbance through tillage (just enough to get the seed into the ground) ; regular crop rotations to help combat the various biotic constraints; CA also uses or promotes where possible or needed various management practices listed below:  utilization of green manures/cover crops (GMCC's) to produce the residue cover;  no burning of crop residues;  integrated disease and pest management;  controlled/limited human and mechanical traffic over agricultural soils. When these CA practices are used by farmers one of the major environmental benefits is reduction in fossil fuel use and greenhouse gas (GHG) emissions. But they also reduce the power/energy needs of farmers who use manual or animal powered systems. Other Important Definitions Conservation agriculture is largely the product of the collective efforts of a number of previous agricultural movements, including no-till agriculture, agroforestry, green manures/cover crops, direct planting/seeding, integrated pest management, and conservation tillage among many others. Yet CA is distinct from each of these so-called agricultural packages, even as it draws upon many of their core principles. This is because CA uses many of the available technologies in unison, resulting in something many believe to be much greater than the "sum of its parts." The following terms are often confused with conservation agriculture: No-till (NT)/ Zero till (ZT) NT and ZT are technical components used in conservation agriculture that simply involve the absence of tillage/plowing operations on the soil. Crops are planted directly into a seedbed not tilled after harvesting the previous crop. Not everyone utilizing no-till technologies adopts other important components of CA. One major difference is that NT or ZT do not necessarily leave residue mulch. Some recent research data suggests this is vital, since without the residue mulch many of the benefits of CA are lost or decreased in value. Conservation tillage/ Minimum tillage/ Reduced tillage These are tillage operations that leave at least 30% of the soil surface covered by plant residues in order to